Hi Stellan, where are you? I'm in Stockholm in my office. I just got here after seeing my eighth child on an ultrasound, so I'm in a good mood. It's beautiful: an energetic little skeleton.

Congratulations! Has it expressed a desire yet to go into acting?

[laughing] Oh God, no, not yet.

How do you feel about so many of your children (1) becoming actors?

Since they're all talented I'm fine with it. It would've been terrible if they'd had a love for this profession and couldn't act. They've grown up knowing it's hard work but they've also seen how much I enjoy it.

A character on The Fast Show called Competitive Dad got his kicks thrashing his children at games. Sound familiar?

I've already lost to mine! I should have pressed them down much earlier in life. Now they're too talented, good-looking and smart.

Even the most despicable person is still a human being. Martin is a psychopath but he has also been destroyed by growing up with a serial-killer father. Psychopaths are so good at imitating feelings. They can fool their own psychiatrists.

Bergman was hyper-intelligent but I never liked him as a person. He was not a good man. All directors are control freaks but he was extreme. He did things to people that were not kosher. He didn't destroy people to make them better actors: he destroyed them to utilise his power.

There's even a fake review: "Skarsgård gives a tremendous transformation as Ingmar Bergman. I didn't see him on screen, I saw Ingmar."

[laughs] That's very funny. I would have to wear a fake wart, because Bergman had a wart on his face for many years.

You're in the superhero extravaganza Avengers Assemble. Were you jealous of your co-stars' costumes?

Not at all. When they have all those fake muscles built in, they need these air-conditioning pumps going into the costumes so they don't die in the heat. In Albuquerque, they built the tops of skyscrapers in the desert and you stand there and pretend you're in New York.

What do you need to be a good actor?

An interest in human beings. Curiosity, playfulness, a certain patience.

You have a reputation as the nicest guy in movies.

My father would tell me: "Remember, no one's worth more than you, and no one's worth less than you." I treat everyone as equals. I can't work if I'm not having fun, and I can't have fun if not everyone is happy.

Are you a calming influence on set?

I have the feeling that Lars uses me like they use those castrated bulls in Pamplona: they send in a couple of them to calm down the others. That's me: a castrated bull.

Footnotes

1. Eldest child Alexander (True Blood) can now be seen in Battleship. Then there's Gustaf, Sam, Bill and non-actors Eija, Valter and Ossian.

2. Von Trier directed Skarsgård in Breaking the Waves, The Kingdom II, Dancer in the Dark, Dogville and Melancholia, and said of him: "I shall probably always have him in mind, if there's a suitable part for him."

4. Charlotte Gainsbourg stars in this story of "a woman's erotic journey from birth to the age of 50." Not to be confused with Rochelle, Rochelle, a young girl's strange, erotic journey from Milan to Minsk.

5. Bergman directed Skarsgård on television in L'école des Femmes and on stage in A Dream Play.

• The Girl With The Dragon Tatttoo is out on Blu-ray and DVD 23rd April